The only connector on the MiFi is the micro? USB connector. I haven't seen anything in the literature that comes with the MiFi that indicates its for anything but charging and hooking up to a PC. I looked on the Wilson site and didn't see anything that looks promising.
there is no rf/antenna jack on the MiFi, but there are ways to wirelessly amplify cellular signal to a mifi.
check out this great article on solutions to boost MiFi cellular signal: http://bit.ly/boostmifi